Bill Gates, who has donated $300 million to support Alzheimer's research, tells CBS News chief medical correspondent Dr. Jon LaPook that he's "optimistic" about disease prevention. Recent studies have shown new antibody drugs to slow cognitive decline among people with early-onset Alzheimer's — a critical finding, given that the disease, as of now, has no cure. Dr. LaPook has more this Sunday. https://cbsn.ws/4oXQkFa | CBS Sunday Morning